Meaning of photomultiplier

pho•to•mul•ti•pli•er

Pronunciation: (fō"tu-mul'tu-plī"ur), [key]
— n.
  1. an extremely sensitive detector of light and of other radiation, consisting of a tube in which the electrons released by radiation striking a photocathode are accelerated, greatly amplifying the signal obtainable from small quantities of radiation.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.